Class 10a buildings (such as a private garage, carport, shed, or the like) are defined as non-habitable buildings in the Building Code of Australia (BCA) and are not permitted to be used for residential purposes without approval from the Local Government (refer Section 119 of the Building Act 1975).
Property owners who therefore wish to use a shed for residential purposes and incorporate habitable rooms in the building, e.g. kitchen, bedroom, living room, dining room, must not do so without first obtaining all relevant approvals to permit this use. In addition, the Class 10a building must be upgraded to the minimum standard of a Class 1a dwelling, as required by the BCA, prior to the building being occupied for residential purposes.
What approvals would I need?
There are typically 2 approvals that are required for such a project:
- Building Approval from a Private Building Certifier to change the classification of the building from 10a to 1a (see below for more information); and
- Plumbing Compliance Permit from Council, to be obtained prior to any plumbing work carried out. Any plumbing or drainage work carried out without approval will need to be inspected and upgraded if necessary to comply with the Plumbing Code of Australia.
What documentation for a Building Approval would I need?
The following information is typically required to be submitted to a Private Building Certifier as part of the building application process (check with your Building Certifier for the exact requirements):
- Completed IDAS application forms 1 & 2.
- QBCC Home Warranty Insurance if a licensed builder is to carry out the work and the work is valued at over $3300.
- Owner-Builder permit if the owner is to carry out the work and the work is valued at over $11,000.
- Portable Long Service Levy receipt if the value of work is greater than $150,000.
- Building approval fee.
Architectural Plans (3 copies)
- Site plan, scale 1:200, incorporating existing buildings, boundary clearances, site levels and north point.
- Floor plan, scale 1:100, fully dimensioned, including door and window sizes, room layouts, and location of hard-wired smoke detectors.
- Elevation plan, scale 1:100, minimum 2 elevations, showing ceiling height & slab height.
Other Documentation (3 copies)
- Energy efficiency assessment.
- Structural design plans – Provide an Engineer’s design for a steel-framed building, OR, provide a bracing layout, timber schedule and tie-down schedule for a timber-framed building.
- A Structural Engineer’s Inspection Certificate/Report may also be required (see below).
Important issues to note
The following points should be considered, as not all Class 10a buildings may be suitable to be converted into a Class 1a dwelling.
The Fraser Coast Planning Scheme and Queensland Development Code (QDC) stipulate minimum boundary clearances for buildings in Queensland. A Class 1a building requires a greater setback to side and rear boundaries than does a Class 10a building in the QDC, typically being 1.5 metres to the outermost projection of the building. In some circumstances when converting a shed to a dwelling, a variation in the setback requirements will be required (in the form of a Concurrence Agency Assessment by Council), if the shed has been constructed within the boundary setback distance required for a dwelling. This may not be approved in all cases, as Council needs to consider the amenity and privacy of residents on adjoining lots.
It will need to be demonstrated that the construction of the shed complies with BCA
requirements. This may require an inspection be carried out by a RPEQ Engineer on the adequacy of an existing slab or structural frame and may result in the upgrading of the building being required.
The applicant will need to demonstrate that the building is provided with a vapour barrier (dampproofing membrane) under the slab, in accordance with BCA requirements, or an equivalent barrier is provided to protect against ground moisture.
All “primary building elements”, as defined in the BCA, must be protected from termite attack. This includes all members which take building loads but also includes door jambs, window frames and reveals, architraves and skirtings. Therefore, a steel framed shed may still need a termite barrier if all of the above elements are not termite-resistant.
Slab and ceiling height
The building would need to comply with BCA requirements for finished slab height to protect
against surface water inundation. In addition, ceiling height requirements for habitable and nonhabitable rooms would need to be met.
Flood and bushfire hazard areas
If the building is located within a flood hazard overlay under the Fraser Coast Planning Scheme and has a defined flood level, there will be a minimum floor level required and may require further assessment by a Building Certifier and Structural Engineer against the QDC MP3.5, Construction of buildings in flood hazard areas. If a bushfire hazard overlay covers the building site, the building may need to comply with the AS 3959, Construction of buildings in bushfire-prone areas, for the appropriate “Bushfire Attack Level” as determined by the Building Certifier.
Converting a shed to a dwelling - Factsheet (PDF,400kB)